Image formation by electrophotography is typically performed through a series of processes, where an electrostatic latent image is formed on a photoconductor, the electrostatic latent image is developed with a developer to form a toner image, the toner image is transferred onto a recording medium, such as paper, and the toner image is then fixed on the recording medium.
As for the developer, known are a one-component developer where a magnetic or non-magnetic toner is used independently, and a two-component toner composed of a toner and a carrier.
As for a system for fixing the toner image, a heat roller system is typically used because of excellent energy efficiency thereof. The heat roller system is a system where a heat roller is directly pressed against a toner image present on a recording medium to fix the toner image onto the recording medium.
In case of the heat roller system, however, there is a problem that a large quantity of electricity is required for fixing the toner image. Accordingly, there is a need for improving low-temperature fixing ability of a toner.
The toner disclosed in PTL 1 has a structure where domain phases are present in a matrix formed of a vinyl resin, and each domain phase contains crystalline polyester particles dispersed in a hybrid resin composed of amorphous polyester and a vinyl resin.
Moreover, the toner disclosed in PTL 2 is a toner of a core-shell structure, where the core contains crystalline polyester domains in amorphous polyester, and the shell is formed of amorphous polyester.
Furthermore, the toner disclosed in PTL 3 has a structure containing two kinds of domain phases; i.e., a domain phase of amorphous polyester and a domain phase of crystalline polyester.